For conversion of three-phase power to dc power, power conversion devices adopt active converters or matrix converters in order to reduce harmonics generated in the power supplies.
Techniques related to the present invention are shown below.    Patent Document 1: Japanese Patent Application Laid-Open No. 2004-215406    Patent Document 2: Japanese Patent Application Laid-Open No. 2004-215408    Patent Document 3: Japanese Patent Application Laid-Open No. 2004-215407    Patent Document 4: U.S. Pat. No. 4,648,022    Patent Document 5: U.S. Pat. No. 6,580,621
Non-Patent Document 1: Boon Tech OOI and three others, “An Integrated AC Drive System Using a Controlled-Current PWM Rectifier/Inverter Link”, IEEE TRANSACTIONS ON POWER ELECTRONICS, pp. 64-71, VOL3, NO1, Jan. 1988
Non-Patent Document 2: E. R. Motto and five others, “Application Characteristics of an Experimental RB-IGBT (Reverse Blocking IGBT) Module”, Industry Applications Conference, 2004. 39th IAS Annual Meeting. Conference Record of the 2004 IEEE, Volume 3, 3-7 Oct. 2004 Page(s): 1540-1544 vol. 3